Rotary concrete-mixer.



E. H. LICHTENBERG.

ROTARY CONCRETE MIXER.

APPLICATION FILED NOV 28. IQIE.

Patented Apr. 1, 1919.

"tlhtl: REE

Yt AiFEFi i W @h h ltlfil ERICK H. LICHTENBERG, OF IVHLVI'AUKEE,WISCONSIN, ASSIGNOB T0 KOEHRING MASI-HNE COMPANY, OF MILWAUKEE,'WISCQ'NSEN, A CUBEORATION.

scream CONCRETE-MIXER.

isconsin, have invented oerlinprovcments in lice tary Concrete-liiixersof which thefollowint: a specification. i,

There is at the present time. a commonly used type of concrete mixerknown as the rotary type, in wl'iich the construction involv theprovision of a rotary drum prod o upon its interior with suitable mixingdevices, supported upon rollersengaging a portion or portions of theexterior ol the drum, and operated so as to revolve loy means ofsuitable driving mechanism.

in this type of mixer it is customary utilize a drum structure whichinvolves the formation exteriorly of the drum and on its 'phery, of oneor more runways or races which runways engage a supporting or rollerscarrying the weight of the roiler drum and its contents and formingpractically anti-friction bearings for the drum.

in the practical use of mixing drums such. as referred to the mixingmeans within the drum com rises devices adapted to out through the aggratcs or materials being mixed. to elevate said. materials and pitch themlaterally toward an end of the drum, and other similarly actinginstruinentalities to reverse the movement of the materials in the drum,all with a view to thorough admixture. of said materials.

it is necessarily incident. to the above operation of the mixing meansof the drum that, various increasing and decreasing thrusts are causedas regards the tendency of the drum 'to move endwise in acting on theload operated upon in the manner set, forth and all endwise thrusts areordinarily received upon the hearing portions between the sup iortingrollers of the drum and the runways on the periphery of the drum.

A large amount of end thrust during the rotation of the drum isfrequently caused as an incident to the use of the mixer when locatedupon e'rades not truly horizontal, and on account of which one end ofthe mix-- lug drum is often lower than the other end or in other wordsthe positioning); of the drum attended by a'ilisposition of the same atan inclination to the horizontal resulting in uneven stresses upon theroller or Specificatiofi of Letters Patent.

111 the county of Milwaukee a.

to v

Patented Apr. 11 1919.

Application filed November as, 191$. Serial No. 133,896.

rollers and runways engaged thereby and consequent end thrust tendenciesof the drum during rotation. v Heretofore it has been common to construct one or and runways above referred to as used in mixerconstruction utilizing endwise pitching' mixing devices, with straighthearing surfaces practically interlocking the inixerwith the rollers toprevent endwise or side play 55 of the drum during rotation, and as aresult, on account of the exceptional end thrust tendencies of the drumin mixing and when supported at an inclination to the horizontal, thecontacting uortions of the runways and rollers have had a shearingengagement to such an extent that a shearing action between these partshas been produced tending to cut into the runways suiiiciei'itly toseriously damage the same, create unusual looseness or play between thesupporting rollers and the drum and obvious resulting disadvantages.Indeed in some instances the wear or cutting away of the runways hasbeen such as to require entire replacement of the heads of the drainwhich are equipped with said runways by reason of integral formationtherewith and the expense and loss aside from the disadvantageousincapacitating of the mixer from the foregoing, noel-zesthe provision ofpreventing means a serious desioeratum in the art.

The object of the present invention has been to so design the runwaysand supporting rollers of mixing machines of the type set forth as toobviate the difficulties to sultingviu the constructions heretoforeemployed and which have been fully presented herein. above endis clearlyset forth in the following detailed description and illustrated in theaccompanying drawings, in whioh Figure 1 is a. sectional View showingthe general construction of the mixing drum, L00 supporting rollers, anddriving gears of f what is known as the Koehring mixer, with theinvention adapted thereto,

191g, 2 is a fragmentary side View bringinn; out more fully the mannerin which the supporting rollers of thedrum engage the side bearingwheels of the runways to accommodate for resistance of 'lateral thrusttendencies of the drum in action.

Fig. 3 is an enlarged sectional View of both of the supporting rollers60 itself resulting 85 The construction employed to the' 95 .one of thesupporting rollers constructed in accordance with the invention;

Fig. 4 is a fragmentary section bringing out more fully the engagingrelation between a supporting roller and the drum in the embodiment ofthe invention; and

Fig. 5 is a fragmentary sectional view showing a modified embodiment ofthe invention.

In the drawings, A denotes a mixing drum of the rotary type having thediagonally disposed blades 1 therein and associated with the elevatingbuckets 2 andthe reversible mixing and discharge chute 3. The manner inwhich the materials in the drum are operated upon by the parts 1, 2 and3 is roughly illustrated in Fig. 1 and discloses how theend thrusttendencies of the drum as an incident to the mixing action are incurred.

The drum A is supported by one or more rollers 4 operating in contactwith the runways 5 on the drum- A, said rollers taking, oi? course, thedown thrust of the drum and its contents during the revolution of thedrum. The rollers 4 are chilled on their peripheries and the runways 5are formed integral with the drum and are comprised of a base or raceportion with which the peripheries of the rollers 4 contact, and a sidewall 5 really consisting of the end wall of a flange 6 likewise formedintegral with the drum structure. Each flange 6, of which two arepreferably provided, formed. integral with the opposite heads of thedrum A, isreally a gear formed with teeth 7 engaged by the drivingpinions 0r gears '8. The gears 8 are driven by the motor used foroperating the'mixing machine including the drum A, the latter. beingdriven directly by the gears 8 meshed with the teeth of the flanges 6.It will be observed that the side wall 5 of the runway 5 is formed on abevel or inclination which may be described as leading diagonally inwardor toward the middle of the drum from the point of 'Iherging with thebase of the runway. Likewise it will be observed from Fig. at that theportion of the rim of each roller 4 engaging with the portion 5' of therunway 5 is pivoted or formed on an inclination corresponding with thebevel of the wall 5. In this man-- ner an effective end thrust bearingisprovided between the parts 4 and 5 and it becomes impossible for theinner edge of the roller 4 at its periphery or rim to engage with theouter edge periphery of the flange .6 and cause a resulting shearingoflor cutting action between these parts which has been incident toprevious constructions wherein the contacting portions of the rollers 4and flanges 6 have been disposed in a flange in that it is drum and eachhaving a beve spective runways the. said plane substantially at rightangles to the axis of the drum and the rollers 4.

As a further detail feature of construction, it may be noted also thatthe teeth 7 formed in the flange 6 for meshing relation with respect tothe gears or pinions 8, terminate short of the end of the flange 6forming the side wall 5 of the runway 5, avoiding any liabilitytherefore of engagement between the rollers 4 and. said teeth. Whetherthe drum A be positioned with its axis at the-outer horizontal or at aninclination to the horizontal, it will be evident that liability ofshearing off of the runway 5 at its end thrust portion or wall 5 iswholly avoided and the same is true in respect to the end thrusttendencies of the mixer drum itself when acting upon its contents inpitching the latter back and forth with respect to the ends of the drumand interiorly of the latter.

7 It will be observed on reference to Fig. 5 that a slightly differentarrangement of the runway 5 roller 4 and gear teeth 7 is provided. Inthis modifiiiation the construction of the roller 4 is substantially thesame as heretofore presented in respect to the ,roller 4. The runway 5however, is spaced from the ring of gear teeth 7 to the extentparticularly that the end wall 5 of the runway is formed in the head ofthe drum at a point a short distance from the adjacent terminals of thesaid teeth 7, a free space being thus provided between the rollers 4when in proper'engagement with the runway 5, and the teeth 7,.Furthermore, the beveled end of each roller 4, and likewise thecorrespondingly shaped end wall 5 of the runway '5, commences in itsextent or formation from a point opposite the base cal drum havingperipheral runways near a its ends, each provided with a beveled side incombination with rollers supporting said one of said redrum havinginterior lifting and deflecting blades extending substantially in thedirection of the beveled contact ofi said rollers with said runways. p

in testimony whereof I ,aflix my signature.

' Enron H. trcnrnnnnne.

gaging a beveled side of ed face ent

